B4 Organisation In Animals Flashcards
Name the five levels of organisation in living organisms
Cells➡️tissues➡️organs➡️organ systems➡️organisms
What is a tissue?
A group of cells with similar structures and functions
What is an organ?
A group of tissues working together to perform a specific function
What is the function of bile in digestion?
Neutralises hydrochloric acid from the stomach and emulsifies fat to form small droplets with a large surface area
What is the function of saliva in digestion?
Lubrication to help swallowing-contains amylase to break down starch
Name three enzymes produced in the pancreas
Amylase
Protease
Lipase
Name the four main components of blood
Red blood cells
White blood cells
Plasma
Platelets
What is the function of platelets?
Form blood clots-prevents the loss of blood and stops wounds becoming infected
Describe three adaptations of a red blood cell
Bi-concave disc shape-large surface area to volume ratio for diffusion of oxygen
Contains haemoglobin-binds to oxygen
No nucleus- more space for oxygen
How do white blood cells protect the body?
Engulf pathogens
Produce antitoxins to neutralise toxins, or antibodies
Name the 5 substances transported in the blood plasma
Hormones
Proteins
Urea
Carbon dioxide
Glucose
Why is the human circulatory system a double circulatory system?
Because blood passes through the heart twice for every circuit around the body-deoxygenated blood is pumped from the right side of the heart to the lungs and the oxygenated blood that returns from the lungs is pumped from the left side of the heart to the body
How does the structure of an vein relate to its function?
It carries blood back to the heart at low pressure-doesn’t need thick elasticated walls, but has valves to prevent blood flowing the wrong way
How does the structure of an artery relate to its function?
It carries blood away from the heart under high pressure- has a small lumen and thick elasticated walls that can stretch
How does the structure of a capillary relate to its function?
It carries blood to cells and tissues -has a one cell thick wall to provide a short diffusion distance
